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WARNING
● The risk of accident is higher if you drive too fast, if you do not keep
your distance to the vehicle in front, and when the road surface is slip-
pery or wet. The increased accident risk cannot be reduced by the brake
assist system.
● The brake assist system cannot defy the laws of physics. Slippery
and wet roads are dangerous even with the brake assist system! There-
fore, it is essential that you adjust your speed to suit the road and traffic
conditions. Do not let the extra safety features tempt you into taking any
risks when driving.
Anti-lock brake system and traction control
ABS Anti-lock brake system (ABS)
The anti-lock brake system prevents the wheels locking dur-
ing braking.
The anti-lock brake system (ABS) is an important part of the vehicle's active
safety system.
How the ABS works
If one of the wheels is turns too slowly in relation to the road speed, and is
close to locking, the system will reduce the braking pressure for this wheel.
The driver is made aware of this control process by a pulsating of the brake
pedal and audible noise. This is a deliberate warning to the driver that one
or more of the wheels is tending to lock and the ABS control function has
intervened. In this situation it is important to keep the brake pedal fully de-
pressed so the ABS can regulate the brake application. Do not “pump”. If you brake hard on a slippery road surface, the best possible control is re-
tained as the wheels do not lock.
However, ABS will not necessarily guarantee shorter braking distances in
all
conditions. The braking distance could even be longer if you brake on gravel
or on fresh snow covering a slippery surface.
WARNING
● The anti-lock brake system cannot defy the laws of physics. Slippery
and wet roads are dangerous even with ABS! If you notice that the ABS is
working (to counteract locked wheels under braking), you should reduce
speed immediately to suit the road and traffic conditions. Do not let the
extra safety features tempt you into taking any risks when driving.
● The effectiveness of ABS is also determined by the tyres fitted
⇒ page 222.
● If the running gear or brake system is modified, the effectiveness of
the ABS could be severely limited.
Traction control system (ASR)*
The traction control system prevents the driven wheels from
spinning when the vehicle is accelerating. The system al-
ways includes ABS
Description and operation of the traction control system during
acceleration (ASR
On front-wheel drive vehicles, the ASR system intervenes, reducing engine
power and preventing the driven wheels from slipping during acceleration.
The system works in the entire speed range in conjunction with ABS. If a
failure occurs in the ABS, the ASR will also stop working.
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176Intelligent technology
The ASR helps the car to start moving, accelerate and climb a gradient in
slippery conditions, where this may otherwise be difficult or even impossi-
ble.
The ASR automatically switches on when the engine is started. If necessary,
it may be turned on or off by briefly pushing the ESC button on the centre
console.
When the ASR is off, the warning lamp is lit. The ASR should normally be
left on. Only in exceptional circumstances, when the slipping of the wheels
is required, can they be disconnected using the ESC button, for example.
● With compact temporary spare wheel.
● When using the snow chains.
● When driving in deep snow or on loose surfaces
● When the vehicle is bogged-down, to free it by rocking.
The ASR should be switched on again as soon as possible.
WARNING
● Remember that not even the ASR can defy the laws of physics. This
should be kept in mind, particularly on slippery and wet roads and when
towing a trailer.
● Always adapt your driving style to suit the condition of the roads and
the traffic situation. The greater safety provided by the ASR should not
encourage you to run any risks.
CAUTION
● To ensure that the ASR works correctly, identical tyres should be fitted
on all four wheels. Any differences in the rolling radius of the tyres can
cause the system to reduce engine power when this is not desired.
● Any modifications made to the vehicle (for example, to the engine,
brake system, running gear or to the combination of wheels and tyres) may
affect the operation of the ABS and ASR. XDS*
Driveshaft differential
When taking a bend, the driveshaft differential mechanism allows the outer
wheel to turn at a higher speed than the inner wheel. In this way, the wheel
that is turning faster (outer wheel) receives less drive torque than the inner
wheel. This may mean that in certain situations the torque delivered to the
inner wheel is too high, causing the wheels to spin. On the other hand, the
outer wheel is receiving a lower drive torque than it could transmit. This
causes an overall loss of lateral grip on the front axle, resulting in under-
steer or “lengthening” of the trajectory.
The XDS system can detect and correct this effect via the sensors and sig-
nals of the ESC.
Via the ESC, the XDS will brake the inside wheel and counter the excess
driving torque of that wheel. This means that the driver's desired trajectory
is much more precise,
The XDS system works in combination with the ESC and is always active,
even when the ASR traction control is disconnected.
Electronic Stability Control (ESC)*
General notes
The Electronic Stability Control increases the vehicle's stabil-
ity on the road. The Electronic Stability Control helps reduce the danger of skidding.
The Electronic Stability Control (ESC) includes the systems ABS, EDL and
ASR
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Electronic Stability Control (ESC)*
The ESC reduces the risk of skidding by braking the wheels individually.
The system uses the steering wheel angle and road speed to calculate the
changes of direction desired by the driver, and constantly compares them
with the actual behaviour of the vehicle. When irregularities occur, for exam-
ple, if the vehicle begins to skid, the ESC brakes the appropriate wheel au-
tomatically.
The forces acting on the braked wheel bring the vehicle back to a stable
condition. If the vehicle tends to oversteer, the system will act on the front
wheel on the outside of the turn.
WARNING
● Remember that not even the ESC can defy the laws of physics. This
should be kept in mind, particularly on slippery and wet roads and when
towing a trailer.
● Always adapt your driving style to suit the condition of the roads and
the traffic situation. The greater safety provided by the ESC should not
encourage you to run any risks.
CAUTION
● To ensure that the ESC works correctly, all four wheels must be fitted
with the same tyres. Any differences in the rolling radius of the tyres can
cause the system to reduce engine power when this is not desired.
● Any modifications made to the vehicle (for example, to the engine,
brake system, running gear or to the combination of wheels and tyres) may
affect the operation of the ABS, EDL, ESC and ASR. Anti-lock brake system (ABS)
The anti-lock brake system prevents the wheels locking during braking
⇒ page 175
Electronic differential lock (EDL)*
The electronic differential lock helps prevent the loss of trac-
tion caused if one of the driven wheels starts spinning.
EDL helps the vehicle to start moving, accelerate and climb a gradient in
slippery conditions where this may otherwise be difficult or even impossi-
ble.
The system will control the revolutions of the driven wheels using the ABS
sensors (in case of an EDL fault the warning lamp for ABS lights up)
⇒ page 71.
At speeds of up to approximately 80 km/h (50 mph), it is able to balance
out differences in the speed of the driven wheels of approximately 100 rpm
caused by a slippery road surface on one side of the vehicle. It does this by
braking the wheel which has lost traction and distributing more driving
force to the other driven wheel via the differential.
To prevent the disc brake of the braking wheel from overheating, the EDL
cuts out automatically if subjected to excessive loads. The vehicle will con-
tinue to function normally without EDL. For this reason, the driver is not in-
formed that the EDL has been switched off.
The EDL will switch on again automatically when the brake has cooled
down.
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178Intelligent technology
WARNING
● When accelerating on a slippery surface, for example on ice and
snow, press the accelerator carefully. Despite EDL, the driven wheels may
start to spin. This could impair the vehicle's stability.
● Always adapt your driving style to suit road conditions and the traffic
situation. Do not let the extra safety afforded by EDL tempt you into tak-
ing any risks when driving, this can cause accidents.
CAUTION
Modifications to the vehicle (e.g. to the engine, the brake system, running
gear or any components affecting the wheels and tyres) could affect the effi-
ciency of the EDL ⇒ page 196.
Drive wheel traction control system ASR
The traction control system prevents the driven wheels from spinning when
the vehicle is accelerating. ⇒ page 175
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179
Driving and the environment
Driving and the environment
Running-in Running in a new engine
The engine needs to be run in over the first 1,500 km
(1000 miles).
Up to 1000 kilometres (600 miles)
– Do not drive at speeds of more than 2/3 the maximum speed.
– Do not accelerate hard.
– Avoid high engine revolutions.
– Do not tow a trailer.
From 1000 to 1500 kilometres (600 to 900 miles)
– Speeds can be gradually increased to the maximum road speed
or maximum permissible engine speed (rpm).
During its first few hours of running, the internal friction in the engine is
greater than later on, when all the moving parts have bedded in.
For the sake of the environment
If the engine is run in gently, its life will be increased and its oil consump-
tion reduced. Running in tyres and brake pads
New tyres should be run-in carefully for the first 500 km.
New brake pads should be run-in carefully for the first 200
km.
During the first 200 km, you can compensate for the reduced braking effect
by applying more pressure to the brake pedal. In case of a sharp braking,
the braking distance will be longer with new brake pads than with brake
pads which have been run-in.
WARNING
● At first, new tyres do not give maximum grip, and require running-in.
This may cause an accident. Drive particularly carefully in the first 500
km.
● New brake pads must be “run in” and do not have the correct friction
properties during the first 200 km (120 miles). However, the reduced
braking capacity may be compensated by pressing on the brake pedal a
little harder.
Braking capacity and braking distance
The braking capacity and braking distance are influenced by
driving situations and road conditions.
The efficiency of the brakes depends directly on the brake pad wear. The
rate of wear of the brake pads depends to a great extent on the conditions
under which the vehicle is operated and the way the vehicle is driven. If you
often drive in town, drive short distances or have a sporty driving style, we
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180Driving and the environment
recommend that you have the thickness of your brake pads checked by a
Technical Service more frequently than recommended in the Maintenance
Programme.
If you drive with wet brakes, for example, after crossing areas of water, in
heavy rainfall or even after washing the vehicle, the effect of the brakes is
lessened as the brake discs are wet or even frozen (in winter). In this case
the brakes should be dried by pressing the brake pedal several times.
WARNING
Longer braking distances and faults in the brake system increase the risk
of accidents.
● New brake pads must be run in and do not have the correct friction
during the first 200 km. However, the reduced braking capacity may be
compensated by pressing on the brake pedal a little harder. This also ap-
plies when the brake pads have to be changed further on.
● If brakes are wet or frozen, or if you are driving on roads which have
been salted, braking power may be lower than normal.
● On steep slopes, if brakes are excessively used, they will overheat.
Before driving down a long steep slope, it is advisable to reduce speed
and change down into a lower gear or range (depending on the type of
transmission). This makes use of engine braking and relieves the brakes.
● Never let the brakes “drag” by applying light pressure. Continuous
braking will cause the brakes to overheat and the braking distance will
increase. Apply and then release the brakes alternately.
● Never let the vehicle run with the engine switched off. The braking
distance is increased considerably when the brake servo is not active.
● If the brake fluid loses its viscosity and is subjected to heavy use, va-
pour bubbles can form in the brake system. This reduces the efficiency of
the brakes.
WARNING (Continued)
● Non-standard or damaged front spoilers could restrict the airflow to
the brakes and cause them to overheat. Before purchasing accessories
please observe the relevant instructions ⇒ page 196, Technical modifi-
cations.
● If a brake system circuit fails, the braking distance will be increased
considerably. Contact a specialised workshop immediately and avoid un-
necessary journeys.
Exhaust gas purification system Catalytic converter*
To maintain the useful life of the catalytic converter
– Use only unleaded petrol with petrol engines, as lead damages
the catalytic converter.
– Do not let the fuel get too low in the tank.
– For engine oil changes, do not replenish with too much engine
oil ⇒ page 212, Topping up engine oil .
– Never tow the vehicle to start it, use jump leads if necessary
⇒ page 256.
If you notice misfiring, uneven running or loss of power when the vehicle is
moving, reduce speed immediately and have the vehicle inspected at the
nearest specialised workshop. In general, the exhaust gas warning lamp
will light up when any of the described symptoms occur ⇒ page 65. If this
happens, unburnt fuel can enter the exhaust system and escape into the en-
vironment. The catalytic converter can also be damaged by overheating.
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Driving and the environment
WARNING
The catalytic converter reaches very high temperatures! Risk of fire!
● Never park where the catalytic converter could come into contact with
dry grass or flammable materials under the vehicle.
● Do not apply additional underseal or anti-corrosion coatings to the
exhaust pipes, catalytic converter or the heat shields on the exhaust sys-
tem. These materials could catch fire when the vehicle is being driven.
CAUTION
Never run the fuel tank completely dry because the irregularity of the fuel
supply may cause ignition problems. This allows unburnt fuel to enter the
exhaust system, which could cause overheating and damage the catalytic
converter.
For the sake of the environment
Even when the emission control system is working perfectly, there may be a
smell of sulphur from the exhaust gas under some conditions. This depends
on the sulphur content of the fuel used. Quite often the problem can be
solved by changing to another brand of fuel. Diesel engine particulate filter*
The diesel particulate filter eliminates soot produced by
burning diesel.
Fig. 128 Vehicle data
sticker on back cover of
the Maintenance Pro-
gramme
Your vehicle is fitted with a DPF (Diesel particulate filter) if the vehicle data
sticker (back cover of the “Maintenance Programme”) lists the PR code 7GG
or 7MG ⇒ Fig. 128.
The diesel engine particulate filter eliminates most of the soot from the ex-
haust gas system. Under normal driving conditions, the filter cleans itself. If
driving conditions do not allow the filter to clean itself (for example, multi-
ple short trips) the filter will be obstructed by dust and pollen and the diesel
engine particulate filter warning lamp will light up. This does not repre-
sent a fault, it is a warning that indicates that the filter has not been able to
regenerate automatically and that you must carry out a cleaning cycle, as in-
dicated in ⇒ page 70.
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182Driving and the environment
WARNING
● The diesel engine particulate filter may reach extremely high temper-
atures; the vehicle should be parked so that the exhaust pipe does not
come into contact with flammable materials underneath the vehicle. Oth-
erwise there is a risk of fire.
CAUTION
● Your vehicle is not designed to use biodiesel fuel. Never, under any cir-
cumstances refuel with biodiesel. The use of biodiesel fuel could damage
the engine and the fuel system. The addition of biodiesel to diesel by the
diesel producer in accordance with standard EN 590 is authorised and will
not cause damage to the engine or the fuel system.
● Using diesel fuel with a high sulphur content may significantly reduce
the useful life of the diesel particulate filter. Your Technical Service will be
able to tell you which countries have diesel with a high sulphur content.
Economical and environmentally friendly
driving
Economical and environmentally friendly driving
Fuel consumption, environmental pollution and wear to the engine, brakes
and tyres depends in large part on your driving style. By adopting an eco-
nomical driving style and anticipating the traffic situation ahead, you can
easily reduce fuel consumption by 10-15%. Some tips on how to help you
reduce pollution while saving money are listed below.
Drive anticipating the traffic situation
A vehicle uses most fuel when accelerating. When you anticipate the situa-
tion, you have to brake less often and, thus, accelerate less. If it is possible, let the vehicle roll with a
gear engaged, for example, if you see a red light
ahead. The braking effect achieved in this way helps to reduce the wear of
brakes and tyres; emissions and fuel consumption are reduced to zero (dis-
connection due to inertia).
Change gear early to save energy
An effective way of saving fuel is to change up quickly through the gears.
Running the engine at high rpm in the lower gears uses an unnecessary
amount of fuel.
Manual gearbox: Change from first to second gear as quickly as possible.
We recommend that, whenever possible, you change to a higher gear upon
reaching 2000 rpm. Follow the “recommended gear” indication that ap-
pears on the instrument panel ⇒ page 60.
Avoid driving at high speed
We advise you not to drive at the top speed permitted by the vehicle. Fuel
consumption, exhaust emissions and noise levels all increase very rapidly
at higher speeds. Driving at moderate speeds will help to save fuel.
Avoid idling
It is worthwhile switching off the engine when waiting in a traffic jam, at lev-
el crossings or at traffic lights with a long red phase. The fuel saved after
only 30 - 40 seconds is greater than the amount of fuel needed to restart
the engine.
The engine takes a long time to warm up when it is idling. Mechanical wear
and pollutant emissions are also especially high during this initial warm-up
phase. It is therefore best to drive off immediately after starting the engine.
Avoid running the engine at high speed.
Periodic maintenance
Periodic maintenance work guarantees that, before beginning a journey,
you will not consume more than the required amount of fuel. A well-serviced
engine gives you the benefit of improved fuel efficiency as well as maxi-
mum reliability and an enhanced resale value.
A badly serviced engine can consume up to 10% more fuel than necessary.